Allocated fixed costs, often called common costs, are costs that are not traceable to a particular product, service, product line, or segment. They are never relevant because the costs are assigned to a number of products.llocated fixed costs, often called common costs, are costs that are not traceable to a particular product, service, product line, or segment. They are never relevant because the costs are assigned to a number of products.
Definition of roost. 1  1a : a support on which birds restb : a place where winged animals and especially birds customarily roost. 2  2 : a group of birds roosting together.
(ËÉÉr i, ËÉªÉr i) n., pl. aerâ¢ies or eyâ¢ries. 1. the lofty nest of a bird of prey, as an eagle. 2. a lofty nest of any large bird. 3. a dwelling located high on a hill or mountain. 4. Obs. the brood in a nest, esp. of a bird of prey.